Remove total order check from equals not equals (doesn't make sense there; total order doesn't define eq or ne methods at all)

Author: joefarebrother

python/ql/src/Classes/Comparisons/Comparisons.qll

@@ -12,7 +12,6 @@
  */
 
 import python
-import Comparisons
 import semmle.python.dataflow.new.internal.DataFlowDispatch
 import Classes.Equality
 
@@ -33,8 +32,6 @@ predicate missingEquality(Class cls, Function defined, string missing) {
 }
 
 from Class cls, Function defined, string missing
-where
-  not totalOrdering(cls) and
-  missingEquality(cls, defined, missing)
+where missingEquality(cls, defined, missing)
 select cls, "This class implements $@, but does not implement " + missing + ".", defined,
   defined.getName()

python/ql/src/Classes/Comparisons/EqualsOrNotEquals.ql

@@ -14,7 +14,14 @@
 import python
 import semmle.python.dataflow.new.internal.DataFlowDispatch
 import semmle.python.ApiGraphs
-import Comparisons
+
+/** Holds if `cls` has the `functools.total_ordering` decorator. */
+predicate totalOrdering(Class cls) {
+  API::moduleImport("functools")
+      .getMember("total_ordering")
+      .asSource()
+      .flowsTo(DataFlow::exprNode(cls.getADecorator()))
+}
 
 predicate definesStrictOrdering(Class cls, Function meth) {
   meth = cls.getMethod("__lt__")